Reference books

HOW CAN I GET the complete cyber security course vol 2, 3, AND 4?

On https://courses.stationx.net/ you can choose specific bundle with those courses or you can choose VIP membership and have access to all courses here.

If you are talking about e-book then we don’t have ebooks for vol 2,3, and 4. If you are talking about the course purchase then you can follow the steps that @Igi talked about in the above post.